Electric circuit and plug connection



April 1, 1941 G. s. BRAUN 2,237,023

l l ELECTRIC CI'RCUIT AND PLUG -CONNECTION Y FiledA April 3, 1939 Patented Apr. 1, 1941 UNITED STATES PATENT oFFicE ELECTRIC CIRCUIT AND PLUG CONNECTION Gwilym Stanley Braun, Strasburg', 0hio, assignor to Knapp-Monarch Company, St. Louis, Mo., a corporation of Missouri Application April 3,-1939, Serial No. 265,657

4 Claims.

An object of my invention is to provide an electric circuit such as the heating element of or 220 volt operation by a simple arrangement of two pairs of prongs, one of which is of ordinary construction and the other including one prong of compound character, making it possible to use a standard cord plug therewith and yet secure different circuit connections with the heating element than when the ordinary terminal prongs are associated with the cord plug.

A further object is to provide a structure of this character which is also adaptable for securing two different heats by use of the two pairs of prongs associated with the heating element.

More particularly it is my object to provide terminal prongs which may be associated with a standard cord plug and one of the prongs being formed of two half prongs insulated relative to each other to separate circuit connections therewith, yet operable upon association of a cord plug socket therewith for both of the circuit connections to be made with the one socket.

Still another object is to provide a cover member for each of the pairs of prongs and means to positively insure that one cover member will be closed when the other one is opened for permitting connection of a cord plug therewith thereby eliminating any exposed live prongs.

With these and other objects in view, 'my invention consists in the construction, arrangement and combination of the various parts of my device whereby the objects contemplated are attained, as hereinafter more'fully set forth, pointed out in my claims and illustrated in the accompanying drawing, in which:

Figure 1 is a plan view of a sadiron showing my electric' circuit and plug connections embodied therein.

Figure 2 is a sectional view on the line 2-2 of Figure 1 showing the parts on a reduced scale and showing theterminal prongs andthe housing therefor in rear elevation.

Figure 3 isan enlarged sectional view on the line 3-3 of Figure 2 showing the prongs in greater detail. J

Figure 4 is a sectional view on the line 4 4 of Figure 3 showing a cord plug associated with one set of terminals.

Figure 5 is a sectional view on the line 5-5 of Figure 3.

Figure 6 is a plan view of a portion of Figure l showing the cord plug associated with another set of terminals on a reduced scale; and

Figure 7 is an electrodiagrammatic view showing the circuit connections and a plug associated with one set of the terminals.

On the accompanying drawing I have used the reference numeral I0 to indicate a sole plate and I2 a cover therefor. A handle for the sadiron is indicated at I3 in Figure 1 and the central part thereof is broken away to show a housing I4.

The housing I4 has a pair of openings I5 and I6 adapted to be normally closed by cover mem bers I1 and I8, respectively. The cover members I1 and I8 are hinged as at I9 tothe housing I4.

The housing" I4 encloses two sets of terminals, one of which comprises prongs P and the other comprises prongs P'. The prongs P and one of the prongs P' are indicated as I9, 20 and 2|, respectively. They are of the usual construction for cooperation with the usual split socket members 22 of a cord plug 23 and are supported by flanges 24 extending upwardly from the cover plate I2. The prongs are suitably insulated with relation to the anges 24 in the usual manner.,

be connected in series or parallel with each other as will hereinafter appear.

Wires 33 and 34 connect the end terminal 29v with the terminal prongs 26 and I9. Wires 34 and 35 connect the other end terminal 30 with the prongs 25 and 20. A wire 36 connects the center' terminal 32 with the prong 2I.

Froir'i'the construction of the parts thus far Y described it will be obvious that when the split socket members 22 of a standard cord plug 23 are associated with the prongs P' as in Figures 1, 4

and '7, the prongs 25 and 26v will be electrically connected together by one of the socket members and that socket member will, be connected with the terminals 29 and 30 of the heating element H. The remaining terminal 32 will be connected K in parallel with each other.

When the cord plug 23 is removed from the prongs P' and associated with the prongs P as in Figure 6 then the two parts of the heating element H will be connected in series. Thus I am able with the use of two sets of prongs, one set of which includes a compound prong of the character disclosed. to use a standard cord plug for either parallel or series connection of the two parts of the heating element H together.

inasmuch as all of the prongs P and P' are alive when the cord plug 23 is associated with either pair of them it is `desirable to have the -cover ll or le for the other pair closed to prevent any one from inserting his finger to a position that would contact with the unused prongs.

I therefore provide the covers il and l@ and also providev a control member 3l therefor consisting of a plate pivoted at 38 to the housing id.

This plate may be swung to overlie the, cover i'las in Figure 4 to retain it positively closed when the cover i8 is opened, and vice versa.

My circuit and plug connections can be used either in connection with two dierent voltages or in connection with one voltage Where it is clesired to have two different heats from the same heating element.

For this purpose I have applied two sets of indicia to the housingld, one of which is provided for two voltages. 'I'he wordv Volts has a pair of arrows extending therefrom indicating "110 and 220. When the control element al is in the position of Figure 6 it covers 1l0. and thereby exposes 220 to indicate that the plug 23 associated with the terminals P under the cover lll makes the proper connections for 220 volt operation.,

When the control element Sli is swung to its other position, then the plug may be associated with the prongs P' or 110 volt operation and "110 will be uncovered.

pair thereof being eective to connect the two halves of the heating element in parallel circuit vwith the cord plug when associated therewith, a

housing for said pairs of prongs, a cover for each pair of prongs, a shiftable control element operable to positively retain one of said covers closed while the other .one is permitted to open and element, one pair of said prongs being connectedv with the end terminals of said heating element and the other pair comprising a single prong and a compound prong, said single prong being connected with said central terminal and said compound prong comprising a pair of semicylindricalv prong elements insulated from each other and associated with each other to provide a compound prong of substantially7 the same size as the single prong, said prong elements being connected, each with one of said end terminals whereby association of a standard-cord plug with one pair of prongs will connect the :two halves of said heating element in series circuit with the cord plug and association of said cord plug with the other pair of prongs will connect the two halves of the heating element in parallel circuit with the cord plug, a housing for said pair of prongs, a

Y cover for each pair of prongs and a shiftable con- When 110 volts only is used, high or low heat can be secured from the heating element H. The indicia applicable for this purpose is indicated in Figure 6 as follows: "110 volts. Hihea and Lo-heat.. Here again the control plate 3l covers one indicia when the other is applicable.

Some changes may be made in the construction and arrangement oi the partsof my device without departing from the real spirit and purpose of my invention, and it ismy intention to cover by my claims any modied forms of struc-` ture, or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:

l. In an electrical appliance, a heating element, two' pairs of terminal prongs, one' pair being eective to connect the two halves of said heating element in series circuit with a. cord plug when associated therewith and the other trol element operable to positively retain either of said covers closed While the other one is permitted to open for associating the cord with th .terminals normally covered thereby.

3. In an electric iron, a housing member, a pair of openings through the Wall of said hous ing member, electrical terminals within eachl of said openings, a hinged coverzfor each opening, and a locking plate pivoted on said housing, said plate being engageablewith either of said fcovers to maintain the cover positively in closed posif tion, said plate being of such dimensions that when `it isswung about its pivot sumciently to releasel one cover, lt simultaneously engages the other cover to maintain the latter closed.

'4. In an electric iron, a housing member, a handle' extending longitudinally thereof, a'pair of openings through the wall of said housing, one on v,each side of said handle, electrical terminals within each of said openings, a cover for each of said openings, and a shiftable control element operable to positively retain one of said covers closed while the other one is permitted to open and vice versa.

GWILYM STANLEY BRAUN. 

